Repairing and revitalizing urban infrastructure is an important part in keeping a city up and running smoothly. Infrastructure is the basic physical and organizational structures and facilities (e.g., buildings, roads, and power supplies) needed for the operation of a society or enterprise and without these our society would crumble. Repairing and revitalizing urban infrastructure can cost upwards of billions of dollars or more but may be one of the most important things to keep up to date. With many current infrastructures giving off toxins into the environment or disturbing natural wildlife, engineering a new infrastructure to solve these issues is imperative yet demanding. While environmentalists and most of the world’s population is for replacing the old infrastructures to help save the environment, funding this extremely large project is massive and over whelming. “Various trends – an increasing emphasis on fiscal decentralization, political democratization in many areas, globalization and the financial liberalization that often accompanies it, growing demands for urban services as urbanization continues in major cities around the world – all argue compellingly for finding ways to help urban areas finance large-scale infrastructure” (Alm, 1). Engineers have been collaborating for years on new ideas and ways to build infrastructure that supports the environment and does not disrupt the ecosystem while still being effective. There is no simple answer on how to redo current infrastructure in a cost efficient manor, however by examining the many aspects of urban infrastructure such as transportation, public bridges and abandon properties new advancements have been made as to why the revitalization is crucial and imperative. 

A few years back, the American Society of Civil Engineers gave various parts of the U.S. infrastructure an average grade of D+. Our infrastructure is aging and failing all across the country. Therefore, the challenge that is faced by engineers today and in the future is to find ways to modernize infrastructure, while being economical. Maintaining infrastructure is not a new concept and has challenged engineers for centuries. Maintaining all the systems is very expensive and requires a lot of work. The US government struggles to maintain its already below average grade. Much of the existing infrastructure such as Water lines, gas lines and sewage lines are buried and have been for over a hundred years. This possesses many problems for maintaining and replacing it (Pollock).  In many cases, records of the locations of underground pipes and cables are unavailable or incomplete. A major challenge is to map and label buried infrastructure, so it can be improved and it can help avoid any damage. GPS scanning is the most efficient and economical solution however with the large, extensive infrastructure that is buried below ground, a total mapping could take years. All of these plans and projects are expensive and can cost upwards of millions of dollars coming from tax payer’s money.

As global warming becomes more of an issue, larger cities are being put to blame do to their large carbon emissions. Infrastructure contributes to greenhouse gas emissions in two ways: through construction, for example the energy footprints of cement, steel and aluminum used during the building process and through the things that go on to use that infrastructure for example cars and trains. According to Dhakal Shobhakar an Associate Professor at the Asian Institute of Technology, “large cities contribute 71% to 76% to energy-related carbon emissions” (Shobhakar, 1). Energy consumption as well as carbon emissions tend to be way higher in urban areas than those in rural areas. This is caused from the constant construction throughout cities, the over use of personal vehicles in a small area as well as the large amounts of public transportation systems such as trains, subways, buses and ferries. With the number of citizens using public transportation diminishing while the number of personal vehicles increases a more economical solution needs to be met. Joseph Sussman exclaims in his article, Grand Challenges in Transportation and Transit Systems “The pathway to a successful adoption and translation of research and innovation for new transportation ideas depends largely on long track records of experiments, failures, trials and errors, redesigns, optimizations, verifications, and technological practicality” (Sussman, 1). Sweden, a large leader in eco-friendly transportation is currently testing a new electrified highway transportation system. They have committed to have a fossil fuel independent transport sector by 2030 and are using large shipping trucks connected to an electrical system to help lower gas emissions. The new trucks are equipped with a pantograph power collector that is mounted on the frame behind their cabs. They are in turn connected to overhead power lines that are above the right-hand lane of the road, using conductive technology created by Siemens. The truck can freely connect to and disconnect from the overhead wires while in motion, operating as electric vehicles when on the electrified road and as regular hybrid vehicles at other times. All of the trucks that will be on the road are hybrid and Euro 6-certified, running on biofuel. These trucks are capable of traveling at speeds up to 55 mph and can only drive in the slow lane of traffic, which could potentially increase traffic flow in some areas. According to Kelsey D. Atherton “There are plans for future tests. Working with Volvo, Siemens plans to test a similar system spanning the ports of Los Angeles and Long Beach” (Atherton, 1).  This new ground shipping technology will also create new jobs for the economy with the need to build new power lines. If ground shipping pollutants can be kept to a minimum and the emission of harmful toxins from fossil fuels diminished, this will help save the ecosystem greatly.

With larger amounts of cars occupying roadways a larger amount of stress is applied to the Major roads and bridges, causing them to fail all across the United States. Problems include potholes, rust covered bridges, and in some cases bridges that fail all together. An example of this can be seen from 2007, in Minnesota, where a bridge collapsed killing 13 people and wounding another 145. This tragedy shows how important infrastructure is throughout the country and that if it is not maintained people could be injured or in extreme cases killed. In Japan, an origami style bridge is being tested over the Hongo River in Fukuyama City. It’s concertina like design is capable of being deployed without any foundations by only a few people in under an hour. The system is compact enough to be transported in a car trailer and its portability makes it easy to deploy in times of emergency such as earthquakes, floods and tsunamis. This bridge can also be deployed as a temporary structure during repair of existing bridges, avoiding interruption to traffic flows. “Usually a crane and a team of technicians is needed to assemble a bridge but not in this case," Dr. Paolo Beccarelli, Assistant Professor in Architectural Structures at the University of Nottingham explained. 

Another large issue with current roadways are potholes. On many roads throughout the country roads have been damaged by weather and by large trucks who utilize them daily. In several cases areas that have been flooded tend to have extensive damage to the roads. Often times the potholes will be repaired and weeks later the pothole will re-occur and possibly be bigger. There is a new technology being used in some places known as “keyholing” to repair potholes. This device cuts a circular in the pavement and then replaces the hole with new cement or asphalt. It is almost invisible when completed and is faster than the usual technique. Due to the circular shape of the new mold the new piece is stronger than traditional repairs and less likely to get stress cracks. The coring truck sets up and cores up to an 18” diameter hole up to 22” deep in the sidewalk or roadway in minutes.  Using a core puller, the core is easily removed, allowing vacuum excavation and the utility repair to proceed. After the repair is complete, the hole is backfilled to the base of the pavement. The bonding agent is mixed with water and poured in. The core is replaced, the excavation and reinstatement site is virtually invisible, and the road can be reopened in thirty minutes (Jarnecke). This method of repair is known to be “green technology” that results in a dramatically smaller carbon footprint when compared to traditional construction techniques. It saves tax payers and utility companies millions of dollars when compared to traditional methods of utility patch repair such as trench work, jackhammers, saw cuts and spoil disposal. Many of these current repair methods use excavation equipment and other large pieces of equipment (e.g., backhoes, dump trucks and pavement breakers) that can produce harmful emissions into the atmosphere as well as account for 80% of the total cost of a repair. (Pollock A.). This new process results in a permanent repair with cost savings up to 60% or more over current excavation and restoration practice. Along with being cheaper, keyholing is a new eco-friendly solution. 

Another possible solution to help re-engineer a new infrastructure is to help develop vacant properties within urban as well as rural areas. Turning vacant properties into green parks/sitting areas or community gardens can help stabilize communities as well as help the environment. Although vacant land is often only associated only with shrinking, or depopulating cities, a study shows that “Expanding cities (boundaries increase in size) with population increases tended to report higher levels of vacant land than did stable cities (boundaries decrease or stay the same in size), which reported higher levels of structural abandonment” (Berke, 1). Areas of lower household income tend to have greater numbers of vacant areas that could be turned into green spaces and used to help increase property values of lots around it. In the late 1970’s, early 80’s residents in New York would transform vacant lots in their communities into green spaces as a way to beautify abandoned properties according to Andy Stone, the New York City director for The Trust for Public Land. People’s primary motivation was to clean up neighborhood eyesores as well as help bring clean fresh air into often dirty and polluted cities. New Yorkers still continue to look for opportunities to green the city that never sleeps. In 2011, Ena McPherson helped turn a vacant lot at 267 Throop Ave. into a community garden now known as Tranquility Farm. Some of these gardens can help by supporting neighborhoods and creating vibrant spaces for community building as well as supporting the local food economy by providing land for entrepreneurs looking to start or scale up a food production business.  Creating these green spaces does not cost large amounts of money but is capable of producing great results such as cleaner air and a more aesthetic view within cities. Obtaining vacant lots from cities is often very easy as well as cheap. As of April 2016, 66,125 vacant parcels were held by the Detroit Land Bank Authority, which has received more than $100 million in federal funds to demolish blighted structures. If you are able to identify a suitable city-owned site, you can contact GreenThumb, which is an organization that coordinates with the city agency in charge about the possibility of a license agreement to allow you to use the space as a garden. Licenses can differ depending on which city agency has jurisdiction over the lots and can range from one to two year interim-use agreements.

There have been many attempts to come up with plans to afford such a large redesign of current infrastructure. With government and state money, funding all of these projects it is tax payer’s money being used. Different scenarios have been discussed to help finance large projects like rebuilding an infrastructure while getting them done in a timely manner. “A debt-financed package of green investments totaling $92 billion annually boosts GDP by $147 billion and generates 1.1 million net new jobs by the end of the first year, with the increased levels then sustained over the next decade” (Bivens, 1). This is a lot of money coming from tax payers and many people would like to see it go to other benefits such as military defense, Social Security or Medicare Hospital Insurance. Although these benefits are essential, the steady destruction of our eco system can speed up the self-destruction of our planet. 

Urban area growth pressures infrastructure affecting buildings, transportation and energy and water systems (Chung). With constant strain applied to many large infrastructures common wear and tear is unavoidable. With much of the old infrastructure giving off harmful emissions into the atmosphere a new plan needs to be advised to oversee a total revitalization of old infrastructure. This multibillion dollar project is known to be one of the 14 greatest engineering challenges due to its complexity and unlimited outcomes. Engineers are focusing on developing new methods for infrastructural engineering as well as ways to communicate the new information to society as a whole. By explaining and stressing the need for new infrastructures such as roadways, bridges and green areas, society may prioritize this large, over whelming project and take evasive action to help correct the negative impacts our current infrastructure holds. It is worth spending the large amount of money to help redesign a new infrastructure, potentially helping to save human lives from the dangers of failing infrastructure as well as keeping the environment in a stable healthy manner. Destroying the ecosystem can only have negative impacts and needs to be considered in planning for a new infrastructure. 
